Title :
A 7μW pH-to-digital converter for quality monitoring of perishable products
Author :
Shalmany, S.H. ; Merz, M. ; Fekri, Ali ; Chang, Zhe ; Hoofman, R. ; Pertijs, Michiel A. P.
Author_Institution :
Delft Univ. of Technol., Delft, Netherlands
Abstract :
This paper describes an energy-efficient smart pH sensor intended for use in RFID tags to monitor the quality of perishable products. The sensor is based on an Extended Gate Field-Effect Transistor (EGFET). In a measurement time of 20 ms, it achieves a pH resolution of 0.05 and an accuracy of 0.1 in a pH range from 3 to 10, while consuming only 7 μW. This level of power consumption, which is orders of magnitude lower than the prior art, is achieved by incorporating the EGFET in an ultra-low-power frontend based on a differential source-follower, and digitizing the resulting pH-dependent voltage using an incremental first-order ΔΣ ADC.
Keywords :
chemical sensors; condition monitoring; field effect transistors; food products; intelligent sensors; quality control; radiofrequency identification; EGFET; RFID tags; extended gate field effect transistor; perishable products; ph-to-digital converter; power 7 muW; power consumption; quality monitoring; smart pH sensor; Clocks; Electrodes; Logic gates; Monitoring; Semiconductor device measurement; Temperature measurement; Temperature sensors; ΔΣ ADC; EGFET; PTAT Voltage; Smart pH Sensor; Temperature Sensor;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII), 2013 Transducers & Eurosensors XXVII: The 17th International Conference on
Conference_Location :
Barcelona
DOI :
10.1109/Transducers.2013.6627125
